1. Field of the Invention
The present invention relates to a recording and reproducing apparatus for file transfer, and in particular to a recording and reproducing apparatus and a file transfer method using a protocol (i.e. DTCP-IP (Digital Transmission Content Protection-Internet Protocol) Version 1, etc.) which transfers a file upon measurement of a round-trip response time to the apparatus on a network and determination that the time is not longer than a predetermined time length.
2. Description of the Related Art
In recent years, the use and ownership of digital devices have extended so widely that even the digital information such as the broadcast contents has come to be usable easily by being transferred on a home network of digital devices. The permission of the unconditional transfer of the contents, however, would result in the wide distribution on the internet, for example, and would pose the problem that the copyright of the contents cannot be protected. On the other hand, a standard called DTCP (Digital Transmission Content Protection) is available to limit the duplication of the contents to a predetermined degree. Further, the use of DTCP-IP, Version 1.1 and subsequent versions (although it is unknown whether Version 1.1 or subsequent versions are applicable in the future, Version 1.1 and subsequent versions are herein collectively referred to as “Version 1.1, etc.”) for transfer on, for example, LAN within a predetermined time by measuring the round-trip response time to the destination can secure the utility of the user while at the same time preventing the limitless distribution of the contents.
Patent Document 1 (Jpn. Pat. Appln. KOKAI Publication No. 2004-199190) discloses a technique for measuring the round-trip response time to the destination to transfer the contents only within a predetermined time on LAN.
In the conventional techniques described above, however, the file transfer to the conventional digital devices of the destination having no limit in the round-trip response time would lead to the subsequent duplication with the limitless round-trip response time, thereby causing inconvenience that the file cannot be transferred to the conventional devices. In that case, the problem is posed that the user holding a conventional device cannot enjoy the digital networking in his home with a built-in home AV network.